Mineral material, such as rock, can be extracted from the ground for crushing by means of either explosions or excavation. The rock may also be natural stone and gravel, or construction waste. Both mobile crushers and stationary crushing applications are used for crushing. The material to be crushed is fed with an excavator or wheel loader to a feed hopper of a crusher or crushing plant, from where the material to be crushed may fall into the throat of the crusher, or a feeder transfers the rock material towards the crusher. The mineral material to be crushed may also be recyclable material, such as concrete, bricks, or asphalt.
Jaw crushers are suitable for, for example, rough crushing at quarries or crushing of construction material. According to the operating principle of the jaw crusher, crushing takes place against jaws, termed fixed and moving jaw.
In a known jaw crusher, side plates of the jaw crusher's frame support an upper end of a pendulum through an eccentric. A rear part of the jaw crusher's frame is fastened between the side plates. Below the eccentric, the pendulum is supported by the rear part of the frame through a toggle plate. A tie rod is arranged between a lower part of the pendulum and the rear part of the frame; the tie rod is spring-loaded and pulls the pendulum backwards towards the toggle plate. The spring influencing the tie rod is tightened with a nut influencing the spring; the nut is moved along a thread formed in the tie rod. Tightening the spring is difficult and requires large force and tools.
The purpose of the invention is to avoid or mitigate problems related to prior art and/or offer new technical alternatives.